The 57 PS pump is one of those over-engineered Chrysler devices, more likely to be found in a Turbine engine that in a road car. That particular PS pump is a nightmare to put together and you must have the proper tooling.
Your PS is probably the aluminum version, (and one year only if I remember correctly) and you probably only need the seals, but I never saw a kit for it anywhere listed. I found a NOS kit at Carlisle last year, but i didn't even open it yet since my PS was working and i only painted it and change the seals.
Remove that thing from the car is another difficult task, specially if the car is complete and running.

As mentioned, the 58 is different, at least the later 58's.
I'm talking about the power sterring box , not the pump.
Strangely enough the earlier 58's used an aluminum steering box,
whilst the later 58's used what they called "Constant control power steering"
and that box (power steering unit) was made of cast iron.

How do I know?

Because I had to have the power steering box in my 58 New Yorker Convertible rebuilt due to bad leaks
which were soooo bad that the lucas stop leap was no help at all.

I used Firm Feel to rebuild the box.
They are "Mopar Experts" as they used to race them.

Thank you gentlemen for your replies...since it sounds like a nightmare in the making, i will go the Lucas route for now....when I can't deal with that any longer I'll try the rebuilder as mentioned here...thanks again guys...
billy

Billy,
Is it the power steering pump on the engine that is leaking or is it the gear that is mounted down on the frame? I can probably give you the seal and bearing numbers if its for the aluminum bodied Thompson power steering pump.
Bob

No, the PS was working fine when removed so I only replace the exterior seals. 57 aluminum PS is something not to mess with it, there is not a kit to repair them as far as I know, all the kits start from 58 which is a complete different unit.